1. Field of the Invention
This invention relates to an observation apparatus provided with an immersion objective lens in which a liquid is interposed between an observation object, such as a living specimen, and an objective lens placed below the observation object and thereby observations are carried out, and in particular, to an observation apparatus provided with an immersion objective lens which is suitable for a microplate sample observation and a time-lapse observation, or an observation combining these.
2. Description of Related Art
In a conventional inverted microscope provided with an immersion objective lens, a common method of supplying a liquid to the immersion objective lens in microscopy is to manually pour the liquid by using a pipette. However, when a plurality of specimens are observed like the microplate sample observation and the time-lapse observation, or when a particular specimen is discontinuously observed for a long term, it is troublesome to manually pour the liquid with the pipette each time the necessity arises, and in addition, this imposes a load on a viewer. Thus, in the observation in which the inverted microscope provided with this type of immersion objective lens is used, the structure that the liquid can be automatically supplied to the immersion objective lens is proposed, for example, by Japanese Patent Publication No. 2004-531765.
FIG. 1 shows the structure that the liquid is automatically supplied to the immersion objective lens, set forth in Publication No. 2004-531765. In FIG. 1, a supplier 51 provided as a liquid pouring means for supplying the liquid to the immersion objective lens is fixed to the immersion objective lens 52, and a supply tube 51a provided at the top of the supplier 51 extends close to a top lens 52a of the immersion objective lens 52 from the side of the immersion objective lens 52. The structure is such that the liquid can be automatically poured, through the supply tube 51a, between the top lens 52a of the immersion objective lens 52 and a specimen 54 supported by a specimen holder 53.
In the structure set forth in Publication No. 2004-531765, a trough-shaped absorption means 55 provided as a discharge means is placed around the immersion objective lens 52 and a discharge tube 56 is connected to the absorption means 55. A liquid flowing from the top lens 52a of the immersion objective lens 52 is stored in the absorption means 55 so that a stored liquid can be discharged through the discharge tube 56.